n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 2 |
4 | 7 |
5 | 25 |
6 | 108 |
7 | 492 |
8 | 2431 |
9 | 12371 |
10 | 65169 |
11 | 350792 |
12 | 1926372 |
13 | 10744924 |
14 | 60762760 |
15 | 347653944 |
16 | 2009690895 |
17 | 11723100775 |
18 | 68937782355 |
19 | 408323229930 |
20 | 2434289046255 |
21 | 14598011263089 |
22 | 88011196469040 |
23 | 533216750567280 |
24 | 3245004785069892 |
25 | 19829768942544276 |
26 | 121639211516546668 |
[1,1,1,2,7,25,108,492,2431,12371,65169,350792, 1926372,10744924,60762760,347653944,2009690895, 11723100775,68937782355,408323229930, 2434289046255,14598011263089,88011196469040, 533216750567280,3245004785069892, 19829768942544276,121639211516546668] |